Do I need to put a stamp on an RSVP envelope if they can rsvp via e-mail?

Yes, you should put a stamp on the envelope.

I would just so you don't have an excuse.

I agree with PP.

I am putting stamps on all mine. I just feel it would be rude to not have postage paid for them.

Yes! Put a stamp on them. Reading so many threads about RSVPs, and guests not returning them, i would suggest the stamps.

Stamp it

Even with stamps it's been difficult getting a response back, don't give them any more reasons not to rsvp.

Yes, stamp 'em. And no matter how easy you make it, they still won't all take the time to send them. I have only had 3 out of 60 RSVPs come in the mail and the due date is a week away, invites were mailed a month ago.

If you are giving them the option of mailing, stamp it.

Seriously, what are you doing 100 invites, 45 bucks is nothing in the grand scheme of the wedding,

I stamped all of mine - I think that you will have a much harder time getting rsvp's back for those who aren't that online user friendly and it may create more hassle for you in the long run.

I'm only doing online RSVPs.

I wools put a stamp on them!!

I totally forgot to put stamps on the majority of my RSVP envelopes lol .. Oops! I put on them though to RSVP via Facebook, calling/text or email though..

Yes. People are horrible about RSVP'ing anyway. Don't give them another way to screw you up.

Honestly, in my opinion, ettiquette is really dependent on your group. Our friend sent the younger crowd Save the Dates by email. And not a single person had a problem with that. Saved them stamps and money on cards, and all of us preferred email anyways since we had an electronic version to keep with us instead of a paper one to lose. My cousin had a small reception after having a ceremony previously. She didn't have return RSVPs at all. She just had a phone number or an email. Because she knew none of us would mind and the younger people would be better with email and the older people would want to call and chat up congratulations anyways. I really think this is on a case by case basis. Basically, everything about weddings is a case by case basis. My other cousin had a reception in a barn where their friend's wedding gift was buying and grilling their food. None of us cared. But we have also had people in the family spend lots of money and get fancy Cake Boss-like cakes. So do whatever you feel is appropriate for your guests. I wouldn't mind at all if you only had an email RSVP for the younger crowd but stamped cards for the older crowd.

If you're giving them the option to RSVP via mail...then I'd say yes.